Tuesday, January 17, 2006

 

Pace and bounce

"Pace and bounce" is almost treated as a single word by several cricket writers/commentators.
But the truth is the following: Although pace and bounce are correlated quantities, the presence of one does not guarantee the other. I will show both empirically and deductively that this is the case.

The bounce in the pitch directly relates to the the coefficient of restitution between the cricket ball and the pitch. Intuitively it is a measure of elasticity of the collission between the cricket ball and the pitch.
On the contrary, pace of the pitch is related to the coefficient of sliding friction between the cricket ball and the surface of the pitch. The greater the friction, the greater the decelaration of the cricket ball on contact and lesser the pace of the pitch. (Note that the "spin" the pitch offers is again directly related to the
friction of the pitch -- greater the friction, the greater the ball would grip and thus greater the turn)
Clearly these (friction and elasticity) are independent quantities and thus one does not guarantee the other.

Now I will give you real world examples: Consider the pitch in Durban, South Africa. This is a pitch which has real steep bounce. (Infact I would say this is the bounciest pitch in the world--along with perth). But the durban pitch, unlike perth, lacks pace. Recall the instance when Sachin nonchalantly hooked Andrew caddick for a six in the 2003 world cup, remember how the ball sat up after pitching--there was bounce but it was slow bounce. I would group the pitches in Mumbai (Wankhede) and Harare into this category.

The other case , pace but not bounce is relatively rare to find. But I think the Sabina Park, Jamaica and the Basin reserve, Wellington pitches are good examples. Recall the "glassy" Sabina Park pitch, where the ball zips off the surface albeit without steep bounce. This pitch really behaves as if it were hard glass. A glassy surface, being really smooth does not decelerate the ball on pitching and hence the fast pace. Even the subcontinental pitches (example chennai, Lahore) have good pace in them, when there is some dew in the pitch. The dew in the pitch is like the "lubricant" that reduces the friction of the pitch, increasing the pace considerably. This phenomenon is widely observed in the subcontinent in the day and night matches.
Recall the latest icc champions trophy finals (rained off) held in Colombo. The khettarama stadium is an inherently slow surface. The Srilankans struggled in the first half because of the sluggish surface making only 200 or thereabouts. But recall when the Indians batted, how the ball was coming on to the bat making shot making more easier. The two square cuts by Sehwag off Dilharo Fernando are still etched in my memory. (Unfortunately both the finals were rained off).

But I have to accept , on an average, there is good correlation between pace and bounce and this is what justifies its usage.

My ranking of pitches according to "pace+bounce" factor : (descending)
  1. WACA, Perth -- (What a pitch!!! how I wish to watch Sachin bat on it more frequently...)
  2. Wanderers (Jo'burg) Gabba(Brisbane), Oval (London)
  3. Sabina Park, Basin Reserve, MCG, Durban, Mumbai
  4. Chennai, Lahore, Karachi, SSC colombo (only when there is dew), SCG, Lords
  5. Bangalore, Adelaide, Trinidad, Auckland
  6. Sharjah, Calcutta, Colombo (Khettarama)


Comments:
a similar detaild one on spinnin tracks is most welcome///
'sensational' bloggin son...keep it going
 
Thanks Bk.
 
i have some discrepencies in the categorisation. Chennai for sure bounces more than mumbai....but again, the presence of red clay in the mumbai surface causes some amt of extra bounce..could u explain the parameters used for the rating? just curious...the work was so interesting, it jus provokes me to ask more questions...btw did u mean, pace + bounce, where its 0.5p + 0.5b to arrive at a final number on which u rate pitches?
and one more thing, does the inclined surface at lords (although the breadth of the pitch is at an angle) affect the behavior of ball's bounce and pace?
 
Actually Harish,

The "rating" of pitches that I had
given is more subjective. I just
rated the pitches instinctively
and I agree it is highly debatable.

Are you saying that the lords pitch
in inclined even lengthwise. (I am aware of the breadthwise slope, but this is news to me.)

The breadthwise slope, as you might be knowing, definitely aids lateral movement, but does not affect the pace/bounce greatly.

The lengthwise inclination would definitely affect the pace and bounce.

Thanks for the comment.
 
Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?